JP2024105679A - Detection and correction of a person's current refractive error and current fluctuations in accommodation - Google Patents

Abstract

To provide a method for detecting variation of a present refractive error of a person.SOLUTION: The current invention relates to a method for detecting variation of a present refractive error of a person. The method includes a step (S1) for acquiring an optical instrument including an optical lens whose refractive function corrects initial refractive error of a person. The optical instrument further includes a processing circuit including a processor operably connected to a memory. The method includes a step (S6) for acquiring present value of a parameter by using the memory, and the present value shows variation of an initial refractive error of the current refractive error of the person. The method includes a step (S7) which uses the processing circuit to detect variation of the initial refractive error of the present refractive error of the person on the basis of the acquired present value of the parameter.SELECTED DRAWING: Figure 4

Description

The present invention relates generally to optical products, and more particularly to a method, computer program, computer storage medium, processing circuitry, and optical device for detecting a change in a person's current refractive error or a change in a person's current accommodation, and a method, computer program, computer storage medium, processing circuitry, and optical device for correcting a person's refractive error or accommodation deficit.

Between two appointments with an eye care practitioner (ECP), a person's refractive error can naturally change.

Common refractive errors include myopia, hyperopia, and astigmatism.

Myopia corresponds to the eye focusing light in front of the retina instead of on it. As a result, distant objects appear blurry.

Hyperopia corresponds to the eye focusing light at its optic axis rather than on the retina. As a result, nearby objects appear blurry.

Astigmatism refers to an eye that does not focus light evenly on the retina. As a result, both near and distant objects appear blurry.

In particular, it has been demonstrated that when a person's myopia is undercorrected, i.e. when the current prescription for compensating for said myopia with an optical device is more advanced than the corresponding original prescription for the optical device that the person normally wears, the myopia progresses more quickly than if it were perfectly corrected.

Myopia is a common refractive error, currently affecting approximately one-third of the population. High myopia poses a higher risk of retinal and choroidal disease. Several methods and products are used to slow the progression of myopia. Of these solutions, corneal orthodontic contact lenses, soft confocal contact lenses, topical medications such as atropine and pirenzepine, and progressive or confocal ophthalmic lenses have been shown to be somewhat effective through randomized controlled trials.

Slowing the progression of myopia as early as possible after its onset is important and could potentially benefit millions of children and adults worldwide.

A strategy to detect myopia progression as soon as possible after its onset is to schedule regular ECP appointments. However, this strategy is not very practical. Even during controlled trials, visits for refractive error evaluation are no more than every 6-12 months. It is not uncommon for myopic children to be exposed to blurred vision due to myopia progression several months after each ECP examination and the fabrication of new glasses. The glasses used at that time no longer fit the advanced refractive error properly. Besides these clinical studies, the interval between two visual acuity tests in daily life can be 18-24 months. Longer intervals can also depend on the inability to make or visit an eye specialist appointment and the child's tolerance of blur. Children may only inform their parents after experiencing significant defocus. Many studies have shown that the more a child is exposed to blurred vision, the faster the rate of myopia progression.

Another common eye condition that is treated herein as a type of refractive error is presbyopia, which is part of the normal aging process and therefore will affect everyone eventually.

As the eye ages, it tends to focus light behind the retina instead of on it. As a result of insufficient accommodation, the ability to focus sharply on nearby objects gradually decreases. As a result, nearby objects appear blurry.

Detecting the progression of presbyopia, and perhaps tailoring the correction provided to it, could potentially benefit millions of adults worldwide.

In the patent application EP 1 239 636 A1, it is proposed to adjust the power of the variable lens via the measurement of the user's refractive error by means of an autorefractometer included in the device. However, this solution does not provide the desired effect in terms of detecting changes in refractive power, since the autorefractometer is not transparent and therefore cannot be worn continuously to perform continuous measurements. Furthermore, the use of objective measurements for refractive power measurement is known to be inaccurate, so that the refractive power provided by the variable lens may not perfectly correct the user's visual error. This may lead to an increase in the refractive error rather than a reduction in the change in refractive power.

International Publication No. 2018/213010

In this regard, it is necessary to estimate the change in a person's refractive error in a timely manner. Depending on this change, it is also necessary to identify an updated refractive correction suitable to correct the person's current refractive error.

An embodiment of the present invention provides a method for detecting variation in a person's current refractive error, the method comprising:
a) obtaining an optical instrument including an optical lens, the optical lens having a refractive function adapted to correct a primary refractive error of a person, the optical instrument further including a processing circuit including a processor operatively connected to a memory;
b) using the memory to obtain current values of the parameters, the current values being indicative of the variation of the person's current refractive error relative to the initial refractive error;
c) detecting, using a processing circuit, a variation of the person's current refractive error relative to the initial refractive error based on the obtained current values of the parameters;
including.

"Refractive error" includes myopia, hyperopia, astigmatism, presbyopia, and any combination thereof. In the case of presbyopia, "refractive error" actually refers to a lack of accommodation.

Initial refractive error should be understood as the refractive error at the baseline point in time.

Current refractive error should be understood as the refractive error at the current time, which is later than the reference time.

Embodiments of the present invention further provide a processing circuit including a processor operatively connected to the memory, the processing circuit configured to perform the above-described method.

Embodiments of the present invention further provide an optical instrument including an optical lens whose refractive function is adapted to correct a primary refractive error of a person, and the processing circuitry described above.

The optical instrument may further include one or more sensors adapted to obtain the current value of the parameter, and the processing circuitry may further include a communication interface with the one or more sensors.

Embodiments of the present invention further provide a computer program comprising one or more stored sequences of instructions accessible to a processor and which, when executed by the processor, causes the processor to perform one of the steps of the aforementioned methods.

Embodiments of the present invention further provide a storage medium, or "memory," for storing one or more stored instruction sequences of the computer programs described above.

The above-mentioned method, computer program, storage medium, processing circuit, sensor, and optical device are capable of detecting a variation in a person's current refractive error relative to an initial refractive error. This effect is achieved in particular by the common feature of using a memory to obtain current values of parameters, the current values being indicative of said variation.

Thus, for example, a processing circuit integrated in the eyeglasses normally worn by a person can determine whether the refractive function of the optical lenses of the eyeglasses still matches the person's current refractive error. If not, an updated refractive function suitable for compensating for the person's current refractive error can be identified.

For example, as a result, changes in the child's myopia can be monitored and a refractive function suitable for compensating for said myopia can be updated, eliminating the need to schedule frequent visits by a clinician, while at the same time, a correct assessment of the refractive power of the eye is simplified over known methods, as it is assessed without requiring any input from the child.

In one embodiment, the processor and memory are operatively connected to a first sensor adapted to measure a value of the parameter when the optical device is worn by the person, and the method includes:
measuring a current value of said parameter using a first sensor, the optical device being worn by the person;

The first sensor allows for an immediate assessment of changes in the person's refractive error. The optical instrument is therefore an independent device capable of assessing said changes.

In an embodiment, the first sensor is adapted to measure a physiological parameter of a person wearing the optical device, the physiological parameter being indicative of a variation in the person's current refractive error relative to the initial refractive error.

Physiological parameters of the person wearing the optical device are measured or monitored to provide objective values that are collected and analyzed to estimate the change in the person's refractive error.

In one embodiment:
the first sensor is a squint motion sensor,
the physiological parameter being the occurrence of squinting movements in a person wearing the optical device,
The step of measuring the current value of said parameter comprises the step of detecting, using a squinting movement sensor, the occurrence of a squinting movement of the person wearing the optical instrument.

Squint sensors are non-invasive and can record indicators that indicate that the optical device wearer's current vision may be blurred. Recording such indicators can be useful, for example, to detect a decline in a child's vision even if the wearer does not actively identify this decline.

In one embodiment:
the first sensor includes at least one electrode configured for electroencephalography;
each of the at least one electrode is positioned to contact the forehead or the occipital region of the person when the optical device is worn by the person;
- the physiological parameter is the electrical activity of the brain of the person wearing the optical device,
the step of measuring the current value of said parameter comprises a step of analysing, by means of at least one electrode, the electrical activity of the brain of the person wearing the optical device;

Electrodes for electroencephalography are non-invasive and are already present in several commercially available head-worn accessories for various purposes. By recording and analyzing electroencephalograms over a period of time, neuronal activity can be detected and a high incidence of neuronal activity, i.e. a higher number of occurrences of neuronal activity in a given viewing situation, can be associated with the perception of increased accommodation or blur by the person wearing the optical device. Said increased accommodation or perception of blur is an indication that the person's current refractive error has changed with respect to their initial refractive error.

In one embodiment,
the memory stores at least one indication of a reference viewing condition;
the optical instrument further comprises at least one second sensor adapted to measure said viewing condition parameters when the optical instrument is worn by the person;
the method further comprises the step of obtaining, by at least one second sensor, at least one indication of the current viewing conditions;
The step of detecting the variation of the person's current refractive error with respect to the initial refractive error is further based on a comparison of at least one indicator of the current viewing conditions with at least one indicator of the reference viewing conditions.

The reference viewing conditions allow a global view by comparing measurements from a first sensor only if they correspond to similar viewing conditions detected by a second sensor.

In one embodiment, the at least one second sensor is a lighting conditions sensor, and the viewing conditions parameter is indicative of the light intensity of the scene seen by the person through the active refractive lens while the first sensor is measuring a current value of the parameter.

By measuring the light intensity of the scene, bright atmospheres can be detected, in which case, for example, squinting may be unrelated to changes in refractive error.

In one embodiment, the at least one second sensor is a distance sensor, and the viewing condition parameter indicates the distance between the active refractive lens and an object that the person is viewing through the active refractive lens while the first sensor is measuring the current value of the parameter.

In this way, it is possible to determine whether the person wearing the optical device is currently viewing at a distance, intermediate or near distance. Any current measurements by the first sensor can therefore be associated with distance, intermediate or near viewing activity. Thus, changes over time, for example squinting movements or brain waves, during near, intermediate or distance viewing activities in particular, can be determined. Changes in a particular eye anomaly can therefore be accurately monitored by selecting only measurements from the first sensor during viewing activities corresponding to a particular viewing distance.

In one embodiment, the optical lens is an active refractive lens and the method comprises:
The method further includes using the processing circuitry to generate an alert to the person if the detected variation exceeds a predetermined threshold.

The alert could allow the person to control the active refractive lens to adjust the correction to suit their needs.

An embodiment of the present invention further provides a method of correcting refractive error in a person, comprising:
a) obtaining an optical device including an active refractive lens, the refractive function of which is adapted to correct a primary refractive error of a person, the optical device further including a processing circuit including a processor operatively connected to a memory and a communication interface with the active refractive lens;
b) using the memory to obtain current values of the parameters, the current values being indicative of the variation of the person's current refractive error relative to the initial refractive error;
c) detecting, using a processing circuit, a variation of the person's current refractive error relative to the initial refractive error based on the current values of the acquired parameters;
d) using the processing circuitry to adjust the refractive function of the active refractive lens if the detected variation exceeds a predetermined threshold, and to maintain the refractive function of the active refractive lens if the detected variation is less than or equal to the predetermined threshold;
including.

An embodiment of the present invention provides a processing circuit including a processor operatively connected to a memory and a communication interface with an active refractive lens, the processing circuit being configured to perform the above-described method for correcting a refractive error of a person.

Embodiments of the present invention further provide an optical instrument including an active refractive lens and the processing circuitry described above. The optical instrument may further include one or more sensors adapted to obtain the current value of the parameter, and the processing circuitry may further include a communication interface with the one or more sensors.

Embodiments of the present invention further provide a computer program comprising one or more stored sequences of instructions accessible to a processor and which, when executed by the processor, causes the processor to perform the steps of the above-described method for correcting refractive error in a person.

Embodiments of the present invention further provide a storage medium, or "memory," for storing one or more stored instruction sequences of the computer programs described above.

The above-mentioned method for correcting a person's refractive error, the computer program therefor, the storage medium, the processing circuitry and the optical device all enable an active refractive lens to be automatically driven to correct a person's refractive error, or accommodation, taking into account changes in said refractive error over a period of time. Thus, the person always obtains the correct correction, even if their refractive error changes, and does not need to have their eyes examined by an ophthalmologist.

In one embodiment, the optical instrument includes one or more sensors, the processing circuitry includes a communication interface with the one or more sensors, the communication interface is operatively coupled to the processor and the memory, and obtaining the current value of the parameter includes measuring the current value of the parameter using the one or more sensors.

In one embodiment, the steps of measuring or obtaining the current values of the parameters and detecting variation in the person's current refractive error relative to the initial refractive error are repeated over a period of time.

Thus, changes in the person's current refractive error are monitored over a period of time, so that changes in the current refractive error relative to the initial refractive error can be detected as soon as possible after said changes occur. It is therefore possible to warn that the person's refractive error has changed, or to directly correct the current refractive error.

In one embodiment, adjusting the refractive function of the active refractive lens includes adjusting one or more of the spherical component, the cylindrical component, the axial component, the add power, and the prism component.

Adjusting the spherical component allows for the correction of myopia/hyperopia. Adjusting the cylindrical component and/or axis allows for the correction of astigmatism. Adjusting the add power allows for the correction of presbyopia.

Prismatic adjustments allow compensation for alignment problems that may have gone undetected in the past or may have been induced by changes in the refractive power of active refractive lenses.

In one embodiment, the method comprises:
- obtaining, using a memory, a predictive model of the variation of the person's refractive error over a period of time;
- using a processing circuit to predict current values of the parameters based on the predictive model;
including.

For example, the optical instrument may include a sensor, the current value of the parameter may be repeatedly measured by the sensor over a period of time to form a database, and a predictive model may be established based on this database to predict future measurement results.

By predicting future measurement results, future measurement results can be double-checked and, for example, sensor failures can be detected and indicated.

Alternatively, the optical device may not have a sensor for measuring the refractive error over time, and the predictive model stored in the memory may be based on sociological data. For example, the predictive model may be obtained based on a record of the change in refractive error over time for a human population, in which case the predictive model is also collaborative. Such a predictive model allows to anticipate changes in the refractive error and always provides an up-to-date correction, even without measuring the refractive error over time.

For a better understanding of the description provided herein and its advantages, reference is now made to the following brief description, which should be read in conjunction with the accompanying drawings and detailed description, in which like reference numerals represent like parts:

2 illustrates an example of a processing circuit adapted to carry out a method according to an embodiment of the present invention; 1 shows an example of a general flow chart of a method according to an embodiment of the invention for detecting variation in a person's current refractive error. 1 shows an example of a general flow chart of a method according to an embodiment of the invention for correcting a person's current refractive error variation. 1 shows an example of a general flow chart of a method for detecting and correcting variations in a person's current refractive error according to an embodiment of the invention. 1 illustrates an example of an optical instrument according to an embodiment of the present invention. 1 illustrates an example of an optical instrument according to an embodiment of the present invention.

In the following description and drawings, the figures may not necessarily be drawn to scale, and certain features may be shown in generalized or schematic form for clarity and conciseness or for reference purposes. In addition, while the making and use of various embodiments are described in detail below, it should be understood that many inventive concepts are provided that may be embodied in a variety of contexts, as described herein. The embodiments described herein are representative only and do not limit the scope of the invention. It will also be apparent to one skilled in the art that all technical features defined with respect to a process can be transferred, individually or in combination, to a system, and conversely, all technical features with respect to a system can be transferred, individually or in combination, to a process.

Referring now to FIG. 1, an example of a processing circuit according to an embodiment of the present invention is shown, the processing circuit being adapted to perform a method for detecting and/or correcting a variation in a person's current refractive error.

The processing circuitry includes a processor (PROC) operatively coupled to a memory (MEM).

In one embodiment of the present invention, the processing circuit further includes a communications interface (INT) operatively coupled to the processor (PROC).

The communication interface (INT) may be configured to communicate with one or more sensors (SENS).

The communication interface (INT) may be configured to communicate with one or more active refractive lenses (LENS).

The communication interface may be wired and/or wireless. Various types of wired or wireless technologies are available, the advantages of each of which are well known to those skilled in the art.

Reference is now made to FIGS. 2, 3, and 4, which each show an example of a general flow chart of a method according to an exemplary embodiment of the present invention, respectively:
- detecting a variation in a person's current refractive error based on the current values of parameters indicative of said variation (FIG. 2),
- detecting said variations and correcting them by adjusting the active refractive function of the active refractive lens, as in the embodiment of FIG. 2 (FIG. 3); and - detecting said variations using a predictive model and correcting them by adjusting the active refractive function of the active refractive lens (FIG. 4).
Regarding.

According to each of the examples shown in [Figure 2], [Figure 3], and [Figure 4], an optical instrument is obtained: Obtain the instrument (S1).

The optical instrument includes an optical lens having a refractive function adapted to correct the primary refractive error of one eye of a person.

Of course, the optical instrument may include two optical lenses whose refractive functions are adapted to correct the initial refractive errors of both eyes of the person.

The optical instrument further includes the processing circuitry described above and shown in FIG.

The memory (MEM) stores a computer program executed by the processor (PROC). A general flow chart of the computer program is shown at least in FIG. 2, FIG. 3, and FIG. 4:
- obtaining a current value of the parameter: obtain current value (S6), which is stored in a memory (MEM), the current value being indicative of the variation of the person's current refractive error relative to the initial refractive error;
- detecting, by a processing circuit (CT), a variation of said current refractive error of the person relative to said initial refractive error of the person, based on the current values of the acquired parameters: detection of variation (S7);
including.

The variation of a person's current refractive error relative to their initial refractive error can relate to both monocular and binocular refractive errors.

Various possibilities for obtaining the current value of the parameter (S6) can be implemented, which are described below.

For example, the current value of the parameter may be measured directly by a first sensor (SENS) integrated into the obtained optical instrument and stored in a memory (MEM).

For example, the current value of the parameter may be indirectly determined by the processing circuit (CT) from measurements made by at least one first sensor (SENS) incorporated in the optical instrument, and the measurements are stored in the memory (MEM).

For example, the current value of the parameter may be indirectly determined by the processing circuit (CT) from a combination of measurements by at least one first sensor (SENS) and at least one second sensor, both integrated in the optical instrument, and the measurements stored in the memory (MEM). For example, a combination of measurements of gaze distance, ambient light flux, and eyelid opening may predict a change in the person's refractive error.

For example, the current value of the parameter may be determined by the processing circuit (CT) from the obtained predictive model.

Reference is now made to the exemplary embodiment shown in FIG.
the optical instrument obtained comprises one or more first sensors adapted to measure said current value of a parameter;
the optical instrument obtained further comprises one or more sensors adapted to measure the current viewing conditions;
said current value of a parameter is obtained based on input from at least one or more first sensors integrated in the obtained optical instrument: obtain current value (S6);
- A variation of the person's current refractive error relative to the initial refractive error is detected based on at least the current values of the obtained parameters: detect variation (S7).

At least one first sensor (SENS) is instructed by the processing circuit (CT) to measure a current value of a parameter: measuring current value (S2). The current value thus obtained is transmitted to the processing circuit (CT) and stored in the memory (MEM).

In an embodiment, the step of measuring the current value of the parameter: measuring the current value (S2) relates to a step of directly measuring the variation of a person's current refractive error relative to their initial refractive error.

The current value of the parameter may be recorded, for example, by a first sensor, which may include a combination of one or more infrared (IR) light sources, such as light emitting diodes (LEDs) emitting 860 nm light, mounted on the temple of the optical instrument, and an IR sensor mounted on the optical instrument, such as a camera sensitive in the IR light range and focused to capture a sharp image of a person's eye. Each IR sensor is in the vicinity of a corresponding IR light source and measures the IR light emitted by the IR light source and reflected on the observer's sclera.

The optical instrument may further include a reflective element, e.g. a holographic mirror on the back surface of the refractive lens, designed to reflect the light incident from the IR light source towards the eye. Preferably, the reflective element is such that the light rays incident on the eye are collimated so that they enter the eye parallel to the pupil, although this configuration is not required and the light may be diverging or converging (e.g. +-3D).

The general principle of decentered photorefraction is that emitted light enters the eye, hits the retina, is then reflected by the retina towards a reflective element, and then reflected back to the camera to obtain an image of the person's eye. In the resulting image, a crescent of light is seen above the person's pupil. The size of the crescent of light depends on the person's refractive error.

In an embodiment, the step of measuring the current value of the parameter: Measuring the current value (S2) relates to detecting behavioral and/or physiological changes that may be induced by blurred vision.

In an embodiment, the detected behavioral and physiological blur-induced changes are indicative of EEG variability.

In fact, it is well known that decision-making is primarily carried out in the frontal regions of the brain. When decision-making becomes more difficult as the degree of blur increases during distance vision activity, brain activity patterns change.

Now, referring to Figure 5, an example of an acquired optical instrument adapted to record a person's brain activity patterns over a period of time is shown.

The resulting optical instrument 100 includes two optical lenses 200 mounted in an eyeglass frame and further includes a first sensor 300. The first sensor 300:
- two dry electroencephalography (EEG) sensors 330 placed on the frame of the optical instrument in contact with the skull area close to the forehead when the optical instrument 100 is worn by the person, and optionally
- two dry EEG sensors 340 placed at the ends of the temples of the glasses to record brain activity in the primary visual cortex when the optical device 100 is worn by the person;
including.

The resulting optical instrument 100 further includes one or more second sensors 400 for measuring additional parameters related to the wearer and/or current vision.

These sensors may record cortical activity for various visual tasks, either continuously or for a few minutes at different times of the day. The recorded cortical activity may be analyzed, for example using algorithms based on deep learning principles, to provide feedback on the level of defocus (i.e. "blurring") experienced by the wearer in real time or at the end of the day. Optionally, it may be envisaged to generate a behavioural baseline based on the recorded cortical activity over a period of time, representing the wearer's usual visual habits based on optimal visual correction, and to use the generated behavioural baseline as an indicator of whether current measurements of cortical activity indicate that defocus experiences are currently occurring. For example, brain activity signals recorded during the days and weeks following the last eye examination and wearing of the new device may be used as a baseline.

For near vision, the cortical signal of blurred vision can be used as feedback to force the person, e.g. a child, to adjust correctly on the reading plane. For distance vision activities, the cortical signal of blurred vision can indicate as feedback that myopia has progressed since the last eye exam and that the person should be provided with new glasses. This feedback can be provided at the end of each day, every other day, every week, etc.

In an embodiment, the detected blur-induced behavioral and physiological changes are indicative of a tendency to squint.

By squinting, the size of the pupil can be voluntarily reduced. This action is used, for example, to protect against bright, glaring light by reducing the amount of light entering the eye. It is also well known that squinting allows the observer to see better when they are optically unable to focus. Indeed, narrowing the palpebral fissure reduces the pupil diameter and improves the depth of focus. An increased occurrence of squinting during distance vision tasks is a good marker of myopia progression. As myopia progresses, images are no longer perfectly focused on the retina. Thus, individuals with undercorrected myopia will squint more frequently to reduce the level of blur and be able to read distant objects. Using big data statistics and/or deep learning principles, an increased tendency to squint can be detected in visual situations that should not require such behavior, i.e., in the case of myopic patients, in distance vision and normal lighting conditions, or in the case of hyperopic or presbyopic patients, in near vision and normal lighting conditions.

Now, referring to Figure 6, an example of the resulting optical device is shown, adapted to record changes in squinting tendency over time.

The resulting optical instrument 100 includes two optical lenses 200 mounted in an eyeglass frame and further includes a first sensor 300. The first sensor 300 includes a combination of one or more IR LEDs 310 mounted in the temples of the optical instrument and one or more IR sensors 320 mounted on the optical instrument to measure IR light emitted by the IR LEDs and reflected off the observer's sclera. An overall decrease in reflected IR light indicates an increased tendency to squint.

Alternatively, an electromyography (EMG) sensor may be placed on the portion of the eyewear device that contacts the temples close to the person's eyes. The EMG sensor may therefore record an increase in strength of the eyelid muscles, which indicates an increased tendency to squint.

Thus, if it is detected that the person's tendency to squint increases under normal lighting conditions for distance vision activities, it can be concluded that the person's current vision correction is no longer adequate, that his/her myopia is progressing, and that new vision correction is required.

As a result of the step of measuring the current value of the parameter using any of the first sensors described above in relation to [Figures 2] and [Figure 3]: measuring the current value (S2), a step of obtaining the current value of the parameter: obtaining the current value (S6) is realized, which is stored in memory (MEM).

The stored current values of the parameters can be directly interpreted for the step of detecting variation in a person's current refractive error: Detect Variation (S7).

However, the current values of the parameters can be better interpreted if said current values are reliably linked to the current wearer state (e.g. head posture and/or eye gaze direction and/or viewing distance, etc.) and to the current environmental conditions (e.g. lighting conditions and/or time of day, etc.). Linking the recording to the current wearer or environmental conditions makes it possible to compare any obtained recording with a recording previously obtained under similar wearer or environmental conditions. Any detected deviations can therefore be interpreted as relating only to variations in the refractive power of the user's eyes.

A variety of sensors may be used, and the examples provided and described in detail above are non-limiting. It should also be noted that although the foregoing examples relate to identifying changes in myopia, each may also be applicable to other types of vision impairments, such as presbyopia, hyperopia, astigmatism, etc.

When people are nearsighted, they may squint during distance viewing activities because they cannot see clearly in the distance, but they do not squint during near viewing activities.

In the case of presbyopia or hyperopia, people may squint during near viewing activities if they have problems with accommodation, but not during distance viewing activities. Age can be additional information that allows for the distinction between hyperopia and presbyopia. For example, a person who squints during near viewing activities may be considered hyperopic if their age is, for example, less than 40 or 45 years old, and presbyopic otherwise.

With astigmatism, people squint because they cannot see clearly regardless of viewing distance.

In an embodiment, the obtained optical instrument includes at least one second sensor adapted to obtain a current viewing condition. The at least one second sensor (SENS) is instructed by the processing circuit (CT) to obtain the current viewing condition: obtain viewing condition (S3). The current viewing condition thus obtained is transmitted to the processing circuit (CT) and associated with the stored current value of the parameter and stored in the memory (MEM).

Viewing conditions can be related to the wearer (wearer-related viewing conditions or "observer conditions") or related to the wearer's environment (environment-related viewing conditions or "environmental conditions").

For example, a sensor such as a telemeter may be used to inform the wearer about viewing distance so that the processing circuitry may determine whether the wearer is performing a distance or near viewing activity. Such a viewing distance sensor may be used, for example, in combination with a brain activity recording sensor to optimally analyze changes in brain activity over time to identify, for example, whether the person is experiencing blurring in distance viewing activities.

Furthermore, by knowing whether a person is performing distance or near viewing activities, it is possible to determine whether the recorded changes in the refractive power of the person's eye are, for example, induced by myopic progression or by accommodation. Thanks to this telemetry device, together with a continuous record of the changes in the refractive power of the person's eye, statistics of the accommodative response can be obtained, indicating a possible loss of accommodation in near vision. Many studies have demonstrated that the greater the loss of accommodation, the faster the progression of myopia. Such statistics of the accommodative response can be used for early detection of the risk of myopic progression, even before the myopia actually progresses.

Besides helping to identify the progression of a wearer's refractive error, such sensors can also be useful for checking whether the refractive error is well-corrected during various prolonged daily activities.

For example, a camera pointed at the wearer's eye may detect the wearer's gaze direction. The resulting gaze direction may be associated with a gaze distance estimated by the processing circuitry using an ergorama. For example, a downward gaze direction may be associated with near vision. For example, a gaze direction straight ahead may be associated with far vision.

For example, a light intensity sensor may be used to provide the processing circuitry with an indication of the lighting level of the wearer's environment.

For example, an accelerometer may be used in conjunction with a distance sensor, and in one example, the glasses may be tilted to indicate a short distance. The processing circuitry may determine that the wearer is engaged in a reading activity based on such a combined indication. Conversely, if the glasses are not currently tilted and the gaze distance corresponds to far-sightedness, the processing circuitry may determine that the wearer is engaged in an activity related to far-sightedness.

Based on the stored current viewing conditions, a specific selection can be made from among multiple and/or consecutive records of parameter values that correspond to similar wearer preliminary environmental conditions.

Such a sensor is particularly relevant in combination with a squinting sensor (since squinting can depend on lighting levels).

The current viewing conditions, obtained using any of the second sensors already described with respect to [Figures 2] and [Figure 3] (S3), and stored in a memory (MEM), together with the current values of the stored parameters, can be interpreted to detect variations in a person's current refractive error (S7).

Detect the variation of the person's current refractive error relative to the person's initial refractive error: Detect variation (S7) Various possibilities can be implemented.

For example, the current value of the obtained parameter may be compared to a predefined threshold value. Such a comparison may be useful for monitoring the continuous change in the person's refractive error. For example, such a comparison may indicate whether the person's current refractive error remains within an acceptable range around the initial refractive error.

For example, the current value of the parameter may be obtained repeatedly over a period of time. Variations in the current value of the parameter over time may be compared to a predefined threshold. Such a comparison may indicate, for example, a sudden and unexpected change in the person's refractive error.

For example, the change in the refraction of the person's eye can be identified based on multiple/sequential recordings selected from a larger number of different recordings, which represent similar wearer and environmental conditions. Such identification allows comparing only those recordings corresponding to situations that represent a change in a certain refractive error, which overcomes the accuracy problem of obtaining an accurate refractive change, and also saves memory and processing resources by considering only relevant measurements from any first sensor incorporated in the obtained optical device. For example, in the case of myopia, only the measurements from the first sensor during distance viewing activities need to be considered. For example, in the case of presbyopia, only the measurements from the first sensor during distance viewing activities need to be considered.

In an embodiment, a step of detecting a variation of the person's current refractive error relative to the initial refractive error: after detecting the variation (S7), the processing circuit (CT) generates an alert to the person or a third party.

An alert may be provided to indicate the detected variation and may be used, for example, to order new optical equipment or schedule an appointment with an eye specialist.

In an embodiment, a step of detecting a variation of the person's current refractive error relative to the initial refractive error: based on detecting the variation (S7), the processing circuit (CT) issues a signal to adjust the corrective power of at least one optical lens of the optical instrument to compensate for said detected variation.

The signal may be, for example, an alarm signal intended to provide a visual or audio warning to the person wearing the optical device, so that the person manually adjusts the correction power.

Alternatively, the signal can be a command signal for automatically adjusting the correction power.

Now, referring to FIG.
- the variation of the person's current refractive error relative to the initial refractive error is detected, according to any of the embodiments described above with respect to FIG. 2: detection of the variation (S7);
at least one optical lens of the optical device obtained is an active refractive lens,
The detected variation of the person's current refractive error relative to the initial refractive error is used to adjust the correction power provided by the active refractive lens to compensate for said detected variation: adjustment (S8).

Of course, the steps of detecting: detecting variation (S7) and adjusting: adjusting (S8) can be repeated indefinitely, thereby repeatedly/continuously providing the person with up-to-date corrective powers.

In one embodiment of the invention, the resulting optical instrument is a smart glass, which comprises:
- two active refractive lenses,
at least one first sensor adapted to measure a current value of a parameter indicative of the variation of a person's current refractive error relative to his or her initial refractive error;
at least one second sensor adapted to measure the current viewing conditions;
a computer system implementing the method illustrated in FIG. 3;
including.

An active refractive lens is an optical lens that exhibits a total lens correction power that can be described as a combination of a first lens correction power made for central vision correction and a second lens correction power that is active (in other words, controllable) and provides an individual with additional central or peripheral vision correction.

The first lens correction power can be passive or active and is usually initially matched to the initial refraction, for example the first lens correction power is equal to the prescription prescribed by an ophthalmologist for a person.

Active correction can be achieved through a variety of techniques.

In the wide field Alvarez lens, two plates can be brought together and slid relative to one another. Depending on the relative position of both plates, different correction powers are obtained. The actuation can be manual with various commands (e.g. slider, roller, etc.). In this case, the person can be informed via any kind of human-machine interface (HMI) (directly on the optical device, via an application, via a warning on a terminal such as a smartphone, etc.) when the compulsion power must be changed and how much correction power to add. The actuation can be automatic with an electrically driven motor. In this case, the required correction power can be changed directly and communicated to the wearer.

In wide-field fluid lenses, the shape of the fluid-filled cavity is controlled to provide a variety of corrective powers.

For example, the optical device may include a pump to control the amount of liquid in a cavity, perhaps enclosed between two ophthalmic shells and fabricated on one side with an elastic membrane. When fluid is injected into the cavity, the elastic membrane deforms, thereby changing the power of the lens.

For example, the lens may include a cavity containing a fluid, perhaps enclosed between two ophthalmic shells. The cavity is fabricated from an elastic membrane. The optical device may further include mechanical actuators distributed along the deformable ring and holding the membrane in tension. The mechanical actuators deform the deformable ring at several points, thereby deforming the membrane and changing the power of the lens.

For example, the lens may include an assembly of a first cavity filled with a first liquid having a first refractive index and a second cavity filled with a second liquid having a second refractive index different from the first refractive index, and an elastic membrane as a partition between the first and second cavities. The assembly may be enclosed within an ophthalmic shell, for example having a refractive index close to the first refractive index. The optical device may further include a reversible pump for adjusting the relative amounts of the first and second liquids to deform the elastic membrane.

For any kind of wide field fluid lens, this can be done manually with various commands (e.g. slider, roller, etc.). In this case, the person can be informed when the compensatory power should be changed and how much correction power to add via any kind of human-machine interface (HMI) (directly on the optical device, via an application, via an alert on a terminal such as a smartphone, etc.). The actuation can be automatic via an electrically driven actuator or pump. In this case, the required correction power can be changed directly and communicated to the wearer.

Other technologies of active refractive lenses can also be used, such as liquid crystal electro-optic lenses, which contain liquid crystals arranged according to a pixelated matrix. Each liquid crystal can be controlled to provide a specific power correction. Liquid crystal electro-optic lenses provide finely controlled optical designs. The actuation can be automatic via an electrically actuated active/passive matrix. In this case, the required power of correction can be directly changed and communicated to the wearer.

The refractive function of each active refractive lens is initially set to correct the initial refractive error, if any, of a person based on the initial refractive power of the person's eye. The initial refractive power may be obtained by performing any standard or known power identification process.

Adjusting the correction provided by the active refractive lens to compensate for the detected variations: The adjustment (S8) allows for always providing an appropriate correction for a person with a constantly changing refractive error detected based on measurements over a period of time by the first sensor and, optionally, the second sensor.

Therefore, the optical device provides a correction that is tailored to the individual in that any changes in the individual's refractive error relative to their initial refractive error are taken into account.

Various variations of the concept described above may be recognized. In particular, the optical instrument obtained may not include any sensors, and may not include any measurements collected over a period of time to assess changes in a person's refractive error and provide corrections that take this change into account.

Now referring to FIG. 4, the resulting optical instrument includes at least one active refractive lens and a processing circuit (CT). This implementation can be cost-effective and weight-effective since the optical instrument does not require any sensors.

A prediction model of the change in the person's refractive error over a period of time is obtained by the processing circuit (CT): get model (S4). For the myopia prediction model, the input parameters can be selected from, but are not limited to, age, race, sex, and previous ECP measurement prescription (including sphere, cylinder, or mean sphere). For the presbyopia prediction model, the input parameters can be selected from, but are not limited to, age, sun exposure habits, and previous ECP measurement prescription (including sphere, cylinder, or mean sphere, and add).

In an embodiment, the current value of the parameter indicative of the variation of the person's current refractive error relative to their initial refractive error is predicted by the processing circuit (CT): Predict current value (S5).

The step of predicting the current value may be performed based on the obtained prediction model.

The current value of the parameter indicative of the variation of the person's current refractive error relative to the initial refractive error can therefore be obtained based on a stored prediction model rather than on measurement results: Obtain current value (S6).

A variation in the person's current refractive error relative to the initial refractive error can be detected based on the obtained current values of the parameters.

The detected variation in the person's current refractive error relative to the initial refractive error is used to adjust the correction provided by the active refractive lens to compensate for the predicted variation: adjustment (S8).

Therefore, the optical device provides a correction that is tailored to the individual, taking into account any changes in the individual's refractive error relative to their initial refractive error.

The embodiments described above with respect to [Figure 2] and [Figure 4] may be combined with each other.

In particular, the predictive model described above with respect to [Figure 4] may be combined with measurements from a first sensor and, optionally, from a second sensor described above with respect to [Figure 2].

Indeed, the predictive model can be improved and personalized to the individual using collected data from repeated direct measurements of the change in refractive error of the individual over a period of time. If the measurement of the change in refractive error is obtained indirectly by combining measurements obtained from the first sensor and the second sensor, the quality of the prediction from the predictive model can also be improved by combining said measurements using collected data from repeated measurements using the first sensor and the second sensor over a period of time.

100 Optical instrument 200 Optical lens 300 First sensor 310 LED
320 IR sensor 330 Dry electroencephalography (EEG) sensor 340 Dry EEG sensor 400 Second sensor

Claims (12)

accessible to a processor and, when executed by the processor, causing the processor to
1. A method of refractive error variation based monitoring and alerting, comprising:
The method includes using an optical instrument comprising an optical lens, the refractive function of which is adapted to correct an initial refractive error of the person, the optical instrument further comprising a processing circuit including a processor operatively connected to a memory, the method including:
using said memory to obtain current values of parameters, said current values being indicative of a variation of said person's current refractive error relative to said initial refractive error;
detecting, using the processing circuitry, a variation of the person's current refractive error relative to the initial refractive error based on the obtained current values of the parameters;
using said processing circuitry to generate an alarm if the detected variation exceeds a predetermined threshold;
- using said memory to obtain a predictive model of the variation of the refractive error of said person over a period of time;
- using said processing circuitry to predict said current values of said parameters based on said predictive model;
Including,
The processor and the memory are operatively connected to a first sensor adapted to measure a value of the parameter when the optical instrument is worn by the person, and the method further comprises:
- measuring the current value of said parameter using said first sensor, said optical instrument being worn by said person;
a computer program comprising one or more stored instruction sequences for causing said steps of the method further comprising: The computer program of claim 1, wherein the first sensor is a physiological sensor adapted to measure a physiological parameter of a person wearing the optical device, the physiological parameter being indicative of a variation in the person's current refractive error relative to the initial refractive error. - said first sensor is a squint motion sensor;
- the physiological parameter is the occurrence of squinting movements of the person wearing the optical instrument,
3. A computer program product as claimed in claim 2, wherein the step of measuring the current value of the parameter comprises the step of detecting, using the squinting sensor, the occurrence of a squinting movement of the person wearing the optical instrument. - said physiological sensor comprises at least one electrode configured for electroencephalography;
- each of said at least one electrode is arranged to be in contact with the forehead or the occipital region of said person when said optical device is worn by said person;
- said physiological parameter is the electrical activity of the brain of said person wearing said optical instrument,
- measuring the current value of the parameter comprises analyzing, using the at least one electrode, the electrical activity of the brain of the person wearing the optical device;
3. A computer program according to claim 2. - said memory stores an indication of a reference viewing condition;
said optical instrument further comprises at least one second sensor adapted to measure a viewing condition parameter when said optical instrument is worn by said person;
- obtaining, by said second sensor, an indication of current viewing conditions,
the step of detecting a variation of the person's current refractive error relative to an initial refractive error is further based on a comparison of the indication of the current viewing conditions with an indication of the reference viewing conditions,
2. The computer program product of claim 1. The computer program of claim 5, wherein the optical lens is an active refractive lens, the first sensor is a physiological sensor adapted to measure a physiological parameter of a person wearing the optical device, the physiological parameter being indicative of a variation of the person's current refractive error relative to the initial refractive error, and the at least one second sensor is a lighting conditions sensor, the viewing conditions parameter being indicative of a light intensity of a scene seen by the person through the active refractive lens while the physiological sensor is measuring a current value of the physiological parameter. The computer program of claim 5, wherein the optical lens is an active refractive lens, the first sensor is a physiological sensor adapted to measure a physiological parameter of a person wearing the optical device, the physiological parameter being indicative of a variation of the person's current refractive error relative to the initial refractive error, and the at least one second sensor is a distance sensor, and the viewing condition parameter is indicative of a distance between the active refractive lens and an object that the person is viewing through the active refractive lens during measurement of the current value of the physiological parameter by the physiological sensor. The computer program of claim 1, wherein the steps of measuring the current values of the parameters and detecting the variation of the person's current refractive error relative to the initial refractive error are repeated over a period of time. accessible to a processor and, when executed by the processor, causing the processor to
1. A method for adjusting a refractive function of an active refractive lens, comprising:
The method includes using an optical instrument comprising an optical lens, the refractive function of which is adapted to correct an initial refractive error of the person, the optical instrument further comprising a processing circuit including a processor operatively connected to a memory, the method including:
using said memory to obtain current values of parameters, said current values being indicative of a variation of said person's current refractive error relative to said initial refractive error;
detecting, using the processing circuitry, a variation of the person's current refractive error relative to the initial refractive error based on the obtained current values of the parameters;
using the processing circuitry to adjust a refractive function of the active refractive lens when the detected variation exceeds a predetermined threshold, and to maintain the refractive function of the active refractive lens when the detected variation is less than or equal to the predetermined threshold;
A computer program comprising one or more stored instruction sequences for causing said steps of the method to be performed, A storage medium storing one or more stored instruction sequences of the computer program of claim 9. A processing circuit including a processor coupled to a memory,
1. A method of adjusting a refractive function of an active refractive lens, the method comprising using an optical instrument comprising an optical lens, the refractive function of which is adapted to correct an initial refractive error of a person, the optical instrument further comprising a processing circuit including a processor operatively connected to a memory, the method comprising:
using said memory to obtain current values of parameters, said current values being indicative of a variation of said person's current refractive error relative to said initial refractive error;
detecting, using the processing circuitry, a variation of the person's current refractive error relative to the initial refractive error based on the obtained current values of the parameters;
using the processing circuitry to adjust a refractive function of the active refractive lens when the detected variation exceeds a predetermined threshold, and to maintain the refractive function of the active refractive lens when the detected variation is less than or equal to the predetermined threshold;
A processing circuit configured to perform the method. 1. An optical instrument comprising an optical lens and a processing circuit, the processing circuit including a processor coupled to a memory, the processing circuit comprising:
1. A method of adjusting a refractive function of an active refractive lens, the method comprising using an optical instrument comprising an optical lens, the refractive function of which is adapted to correct an initial refractive error of a person, the optical instrument further comprising a processing circuit including a processor operatively connected to a memory, the method comprising:
using said memory to obtain current values of parameters, said current values being indicative of a variation of said person's current refractive error relative to said initial refractive error;
detecting, using the processing circuitry, a variation of the person's current refractive error relative to the initial refractive error based on the obtained current values of the parameters;
using the processing circuitry to adjust a refractive function of the active refractive lens when the detected variation exceeds a predetermined threshold, and to maintain the refractive function of the active refractive lens when the detected variation is less than or equal to the predetermined threshold;
13. An optical instrument configured to perform a method comprising: